Effects of Fisheries on Eurasian Perch (Perca fluviatilis) in Windermere

Abstract

A review of literature indicated that a wartime (1941–48) trap fishery reduced the Eurasian perch (Perca fluviatilis) population very considerably. An experimental gillnet fishery for northern pike (Esox lucius) from 1944 to 1975 presumably contributed to keeping the perch population low through increased predation. The gillnet fishery reduced the average size of the pike, and their growth rate increased, in turn increasing the predation on younger perch. This predation controlled recruitment to the adult perch population. Pike predation is given as one factor in a model explaining year-class fluctuations. Key words: Percidae, exploitation, year-class fluctuations, Perca predation, year-class model